Enhancing the stretchability of two-dimensional materials through kirigami: a molecular dynamics study on tungsten disulfide.

In recent years, the 'kirigami' technique has gained significant attention for creating meta-structures and meta-materials with exceptional characteristics, such as unprecedented stretchability. These properties, not typically inherent in the original materials or structures, present new opportunities for applications in stretchable and wearable electronics. However, despite its scientific and practical significance, the application of kirigami patterning on a monolayer of tungsten disulfide (WS), an emerging two-dimensional (2D) material with exceptional mechanical, electronic, and optical properties, has remained unexplored. This study utilizes molecular dynamics (MD) simulations to investigate the mechanical properties of monolayer WS with rectangular kirigami cuts. We find that, under tensile loading, the WS based kirigami structure exhibits a notable increase in tensile strain and a decrease in tensile strength, thus demonstrating the effectiveness of the kirigami cutting technique in enhancing the stretchability of monolayer WS. Additionally, increasing the overlap ratio enhances the stretchability of the structure, allowing for tailored high strength or high strain requirements. Furthermore, our observations reveal that increasing the density of cuts and reducing the length-to-width ratio of the kirigami nanosheet further improve the fracture strain, thereby enhancing the overall stretchability of the proposed kirigami patterned structure of WS.